This is a renewal proposal to demonstrate the accuracy and resolution with which one can define myocardial infarction and ischemia using the positron emitting isotope rubidium-82 and carbon-11 amino acids. Rubidium-82 (75 sec. half-life) is available from a table top generator containing strontium-82 (25 day half-life). The detection system is a positron emission tomograph (PET) comprised of 280 rectangular crystals 8 mm wide mounted on a circle of 92 cm diameter. Transverse sections of Rb-82 accumulation are obtained after bolus injections or continuous infusion wherein the specific volume flow is deduced from the ratio of concentration in the myocardium to that in the blood pool. This renewal application emphasizes the development of an optimal strategy for imaging patients and focuses on the evaluation of perfusion in coronary artery disease patients before and after exercise conditioning. The uptake of amino acids in the myocardium will be evaluated using the positron emission tomograph with emphasis on C-11-methionine and taurine uptake.